Install escape devices on fishing gear: Sea turtles

Overall effectiveness category Awaiting assessment
Number of studies: 1
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Effectiveness

not assessed
Certainty

not assessed
Harms

not assessed

Calculating overall effectiveness category

Background information and definitions

Aquatic reptiles may become trapped or entangled in fishing nets (e.g. trawl nets, hoop nets, fyke nets) and traps. Escape devices such as escape holes, sections of larger mesh, or chimneys may be fitted to fishing gear to allow non-target animals to escape after they have entered fishing gear.

Due to the number of studies found, this action has been split by species group. See here for: Tortoises, terrapins, side-necked & softshell turtles; Snakes & lizards or Crocodilians.

For studies that discuss the effect of using devices that exclude reptiles from fishing gear, see Install exclusion devices on fishing gear, and for studies on the effect of using a combination of exclusion and escape devices see Install exclusion and escape devices on fishing gear.

Study locations

Key messages

One study evaluated the effects of installing escape devices on fishing gear on sea turtle populations. This study was in the Gulf of Carpentaria (Australia).

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (0 STUDIES)

BEHAVIOUR (0 STUDIES)

OTHER (1 STUDY)

Unwanted catch (1 Study): One randomized, paired, controlled study in the Gulf of Carpentaria found that trawl nets with escape devices caught a similar number of sea turtles compared to unmodified nets.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A randomized, paired, controlled study in 1995–1995 in seabed areas in the Gulf of Carpentaria, northern Australia (Brewer et al. 1998) found that trawl nets fitted with one of seven escape zone designs (“bycatch reduction devices”) caught similar numbers of sea turtles compared to unmodified nets. No statistical tests were carried out. Nets fitted with escape zones caught turtles at a similar rate (0.14 turtles/tow, 17 individuals) as unmodified nets (0.13 turtles/tow, 9 individuals). The unwanted catch included three species of turtles and three of snakes. The effect of escape zones on the commercially targeted prawn catch varied by design (see original paper for details). Escape zone designs tested included ‘fisheye’, ‘radial escape section’, ‘square mesh window’ and square mesh windows fitted with a number of modifications (see original paper for details). Vessels towed twin Florida Flyer prawn trawl nets from each side of the vessel in trials of one-month duration (sea turtles: February and October 1995). Nets fitted with one of the designs of escape zone and an unmodified net were randomly assigned to either side of the vessel.
Study and other actions tested
Referenced paper
Brewer D., Rawlinson N., Eayrs S. & Burridge C. (1998) An assessment of bycatch reduction devices in a tropical Australian prawn trawl fishery. Fisheries Research, 36, 195-215.

Please cite as:

Sainsbury K.A., Morgan W.H., Watson M., Rotem G., Bouskila A., Smith R.K. & Sutherland W.J. (2021) Reptile Conservation: Global Evidence for the Effects of Interventions for reptiles. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Reptile Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Install escape devices on fishing gear: Snakes & lizards Action Link	Awaiting assessment	3	Synopsis Link
Modify mesh sizes used in fishing gear Action Link	No evidence found (no assessment)	0	Synopsis Link
Install exclusion devices on fishing gear: Sea turtles Action Link	Awaiting assessment	3	Synopsis Link